I wrote a long blog post about a few months ago about the perils of using fullscreen in modern browsers: http://sorcery.smugmug.com/2012/06/06/using-html5s-fullscree..., which is cited as a reference (awesome!). This explains why some of the code looks similar, I'm glad it was helpful.

This library could use error detection and handling as there are situations where fullscreen could be aborted or fail to start.

It's much better to attempt going fullscreen and have callbacks for errors and successfully entering fullscreen mode. Users can have preferences set to not allow it, press ESC during the transition or a number of other scenarios can occur.

There's also some CSS fixes between browsers that could be included. Safari and Chrome don't stretch the element to 100% monitor width and don't apply a background color by default so you can see 'through' the fullscreen window.

That being said it's good someone is working towards something that's relatively cross-browser. The fullscreen API right now is extremely varied but a really awesome tool for advanced web apps.